Academic achievement

Do you have (or are you likely to gain) a good first degree?

For the UK, you're at a real disadvantage if you don't have a 1st or 2:1 (or overseas equivalent). If you dropped a grade or two due to external circumstances, you may find that getting postgraduate qualifications gets you back on track, but it won't be straightforward. If you got a 2:2 or below through lack of motivation or ability ('wrong subject', 'poor teaching' etc), you face an uphill struggle and should seriously consider alternatives to an academic career.

Are you prepared to get postgraduate qualifications, generally a PhD or equivalent?

Some academics don't have PhDs, but they are the exception (for example, they may have extensive relevant professional experience before entering academia). If you are going to be a researcher and supervise others' research (whether PhD students or research staff), getting a PhD demonstrates your professional competence in research.